The protocol review system includes 1) solicitation of cancer center investigators for institutional protocols to be reviewed for access to the shared resources of the cancer center, 2) meetings to review submitted institutional protocols, and 3) a protocol monitoring system to assure timely conduct and review of ongoing protocols. The primary purpose of this core facility is to provide an efficient and economical means by which transgenic mice can be produced for members of the San Antonio Cancer Institute. The establishment of transgenic mouse production capabilities involves a substantial investment both in terms of equipment and in training of personnel and is, therefore, usually prohibitively expensive to individual laboratories requiring only a small number of transgenic mice. Further, only limited options for transgenic mouse production have been available to San Antonio Cancer Institute members in the past, involving either having mice produced commercially or establishing a collaboration with one of the small number of laboratories within the UTHSCSA or CTRC that currently produce transgenic mice. The primary objective of this core is therefore to provide San Antonio Cancer Institute members a means by which transgenic mice can be produced in a timely fashion and at a cost which reflects the actual cost of producing the mice. Additional, related services will include rederivation of pathogen-free mouse lines and embryo cryopreservation.